Wells Fargo & Company Credit Card Complaint

Wells Fargo & Company Credit card department,

Billing disputes Iowa

I transferred a balance that is supposed to be interest free for 15 months, I believe. I also make purchases with the same card I have the transfer balance on. Although I pay my purchase total in full each cycle, I am still being charged interest, when the only balance that is left is my transfer balance. When I called to ask how this can be, it was explained to me that basically my purchases made after I transferred my balance over falls behind the transfer balance amount, so in essence I will never pay off my " purchases '' until I pay off the transfer balance ( which is a substantial amount ), since payments are applied to the oldest transaction first. By them doing it this way, I will forever be charged interest on my " purchase '' totals until the full balance is paid. I have since stopped using that card for purchases, realizing the interest is just going to grow, but this seems very unethical to me. Seems like my purchase balance and transfer balance should be kept separate and payments should be applied to purchases first, since that is where interest currently accrues. Is this ethical?